In this study,a simple and effective ratiometric fluorescence method has been developed for carbaryl detection,utilizing red emissive carbon dots(R-CDs).The underlying principle of this proposed strategy relies on the...In this study,a simple and effective ratiometric fluorescence method has been developed for carbaryl detection,utilizing red emissive carbon dots(R-CDs).The underlying principle of this proposed strategy relies on the rapid hydrolysis of carbaryl under an alkaline condition and production of 1-naphthol with blue-emission at 462 nm.Furthermore,the as-synthesized R-CDs(Em.677 nm),serve as a reference,enhancing the visual tracking of carbaryl through the transformation of fluorescent color from red to blue.The concentration of carbaryl exhibits a commendable linear correlation with the ratio of fluorescence intensity,ranging from 0 to 20μg/m L(R^(2)=0.9989)with a low detection limit of 0.52 ng/m L.Additionally,the described methodology can be used for the enzyme-free visual assay of carbaryl,even in the presence of other carbamate pesticides and metal ions,in tap water and lake water samples with excellent accuracy(spiked recoveries,94%-106.1%),high precision(relative standard deviation(RSD)≤2.42),and remarkable selectivity.This fast and highly sensitive naked-eye ratiometric sensor holds immense promise for carbaryl detection in intricate environments and food safety fields.展开更多
As a fundamental thermodynamic variable, pressure can alter the bonding patterns and drive phase transitions leading to the creation of new high-pressure phases with exotic properties that are inaccessible at ambient ...As a fundamental thermodynamic variable, pressure can alter the bonding patterns and drive phase transitions leading to the creation of new high-pressure phases with exotic properties that are inaccessible at ambient pressure. Using the swarm intelligence structural prediction method, the phase transition of TiF_(3), from R-3c to the Pnma phase, was predicted at high pressure, accompanied by the destruction of TiF_6 octahedra and formation of TiF_8 square antiprismatic units. The Pnma phase of TiF_(3), formed using the laser-heated diamond-anvil-cell technique was confirmed via high-pressure x-ray diffraction experiments. Furthermore, the in situ electrical measurements indicate that the newly found Pnma phase has a semiconducting character, which is also consistent with the electronic band structure calculations. Finally, it was shown that this pressure-induced phase transition is a general phenomenon in ScF_(3), VF_(3), CrF_(3), and MnF_(3), offering valuable insights into the high-pressure phases of transition metal trifluorides.展开更多
Considering that pressure-induced formation of short,strong covalent bonds in light-element compounds can produce superhard materials,we employ structure searching and first-principles calculations to predict a new cl...Considering that pressure-induced formation of short,strong covalent bonds in light-element compounds can produce superhard materials,we employ structure searching and first-principles calculations to predict a new class of boron nitrides with a stoichiometry of BN_(2),which are stable relative to alpha-B and alpha-N_(2) at ambient pressure.At ambient pressure,the most stable phase has a layered structure(h-BN_(2)) containing hexagonal BN layers between which there are intercalated N_(2) molecules.At 25 GPa,a three-dimensional P4_(2)/mmc structure with single N-N bonds becomes the most stable.Dynamical,thermal,and mechanical stability calculations reveal that this structure can be recovered under ambient conditions.Its calculated stress-strain relations demonstrate an intrinsic superhard nature with an estimated Vickers hardness of ~43 GPa.This structure has a potentially high energy density of ~4.19 kJ/g.展开更多
There are few studies on the treatment orientation of psychological counseling and psychotherapy practitioners in China. Additionally,integrative therapy as the first choice is much commoner in less developed areas an...There are few studies on the treatment orientation of psychological counseling and psychotherapy practitioners in China. Additionally,integrative therapy as the first choice is much commoner in less developed areas and among unsupervised practitioners,which reflects the risk of technical confusion relating to the use of integrative therapy in China. The counseling and psychotherapy practitioners are treated as " variables",and researchers are concerned because these " variables" can have a significant impact on the course of treatment and outcomes.Therefore,we analyze the effects of socioeconomic development level on practitioners' treatment orientation. Based on the results,in addition to areas of employment,urban stratification and practitioners' system factors,gender,age,education,professional background,work hours,and other factors affect psychological counseling and psychological treatment practitioners.展开更多
The search for new inorganic electrides has attracted significant attention due to their potential applications in transparent conductors,battery electrodes,electron emitters,as well as catalysts for chemical synthesi...The search for new inorganic electrides has attracted significant attention due to their potential applications in transparent conductors,battery electrodes,electron emitters,as well as catalysts for chemical synthesis.However,only a few inorganic electrides have been successfully synthesized thus far,limiting the variety of electride examples.Here,we show the stabilization of inorganic electrides in the Ti-rich Ti–O system through first-principles calculations in conjunction with swarm-intelligence-based CALYPSO method for structure prediction.Besides the known Ti-rich stoichiometries of Ti_(2)O,Ti_(3)O,and Ti_(6)O,two hitherto unknown Ti_(4)O and Ti_(5)O stoichiometries are predicted to be thermodynamically stable at certain pressure conditions.We found that these Tirich Ti–O compounds are primarily zero-dimensional electrides with excess electrons confined in the atom-sized lattice voids or between the cationic layers playing the role as anions.The underlying mechanism behind the stabilization of electrides has been rationalized in terms of the excess electrons provided by Ti atoms and their accommodation of excess electrons by multiple cavities and layered atomic packings.The present results provide a viable direction for searching for practical electrides in the technically important Ti–O system.展开更多
基金supported by the Natural Science Foundation of the Science and Technology Department of Jilin Province(No.20220101086JC)。
文摘In this study,a simple and effective ratiometric fluorescence method has been developed for carbaryl detection,utilizing red emissive carbon dots(R-CDs).The underlying principle of this proposed strategy relies on the rapid hydrolysis of carbaryl under an alkaline condition and production of 1-naphthol with blue-emission at 462 nm.Furthermore,the as-synthesized R-CDs(Em.677 nm),serve as a reference,enhancing the visual tracking of carbaryl through the transformation of fluorescent color from red to blue.The concentration of carbaryl exhibits a commendable linear correlation with the ratio of fluorescence intensity,ranging from 0 to 20μg/m L(R^(2)=0.9989)with a low detection limit of 0.52 ng/m L.Additionally,the described methodology can be used for the enzyme-free visual assay of carbaryl,even in the presence of other carbamate pesticides and metal ions,in tap water and lake water samples with excellent accuracy(spiked recoveries,94%-106.1%),high precision(relative standard deviation(RSD)≤2.42),and remarkable selectivity.This fast and highly sensitive naked-eye ratiometric sensor holds immense promise for carbaryl detection in intricate environments and food safety fields.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 12034009, 91961204, and 11974134)。
文摘As a fundamental thermodynamic variable, pressure can alter the bonding patterns and drive phase transitions leading to the creation of new high-pressure phases with exotic properties that are inaccessible at ambient pressure. Using the swarm intelligence structural prediction method, the phase transition of TiF_(3), from R-3c to the Pnma phase, was predicted at high pressure, accompanied by the destruction of TiF_6 octahedra and formation of TiF_8 square antiprismatic units. The Pnma phase of TiF_(3), formed using the laser-heated diamond-anvil-cell technique was confirmed via high-pressure x-ray diffraction experiments. Furthermore, the in situ electrical measurements indicate that the newly found Pnma phase has a semiconducting character, which is also consistent with the electronic band structure calculations. Finally, it was shown that this pressure-induced phase transition is a general phenomenon in ScF_(3), VF_(3), CrF_(3), and MnF_(3), offering valuable insights into the high-pressure phases of transition metal trifluorides.
基金Supported by the National Natural Science Foundation of China(Grant Nos.12074154,11904142 and 11722433)the Science and Technology Project of Xuzhou(Grant No.KC19010)+1 种基金the Six Talent Peaks Project and the 333 High-Level Talents Project of Jiangsu Provincethe Natural Science Research Projects of Colleges and Universities in Jiangsu Province(Grant No.19KJB140001)。
文摘Considering that pressure-induced formation of short,strong covalent bonds in light-element compounds can produce superhard materials,we employ structure searching and first-principles calculations to predict a new class of boron nitrides with a stoichiometry of BN_(2),which are stable relative to alpha-B and alpha-N_(2) at ambient pressure.At ambient pressure,the most stable phase has a layered structure(h-BN_(2)) containing hexagonal BN layers between which there are intercalated N_(2) molecules.At 25 GPa,a three-dimensional P4_(2)/mmc structure with single N-N bonds becomes the most stable.Dynamical,thermal,and mechanical stability calculations reveal that this structure can be recovered under ambient conditions.Its calculated stress-strain relations demonstrate an intrinsic superhard nature with an estimated Vickers hardness of ~43 GPa.This structure has a potentially high energy density of ~4.19 kJ/g.
基金Supported by China Natural Science Fund for Youth Foundation(7147310171403100)
文摘There are few studies on the treatment orientation of psychological counseling and psychotherapy practitioners in China. Additionally,integrative therapy as the first choice is much commoner in less developed areas and among unsupervised practitioners,which reflects the risk of technical confusion relating to the use of integrative therapy in China. The counseling and psychotherapy practitioners are treated as " variables",and researchers are concerned because these " variables" can have a significant impact on the course of treatment and outcomes.Therefore,we analyze the effects of socioeconomic development level on practitioners' treatment orientation. Based on the results,in addition to areas of employment,urban stratification and practitioners' system factors,gender,age,education,professional background,work hours,and other factors affect psychological counseling and psychological treatment practitioners.
基金The authors acknowledge funding from the National Natural Science Foundation of China under Grant Nos.11704151,11774127,U1530124,61475063,61505067,11504007,and 11534003the Science Challenge Project,No.TZ2016001+3 种基金Science Challenge Project,No.TZ2016001Program for JLU Science and Technology Innovative Research Team(JLUSTIRT)the program for JLU Science and Technology Innovative Research Team,No.201705The Scientific and Technological Research Project of the“13th Five-Year Plan”of Jilin Provincial Education Department under Grant Nos.JJKH20180772KJ,JJKH20180769KJ,JJKH20180761KJ,and 201648.
文摘The search for new inorganic electrides has attracted significant attention due to their potential applications in transparent conductors,battery electrodes,electron emitters,as well as catalysts for chemical synthesis.However,only a few inorganic electrides have been successfully synthesized thus far,limiting the variety of electride examples.Here,we show the stabilization of inorganic electrides in the Ti-rich Ti–O system through first-principles calculations in conjunction with swarm-intelligence-based CALYPSO method for structure prediction.Besides the known Ti-rich stoichiometries of Ti_(2)O,Ti_(3)O,and Ti_(6)O,two hitherto unknown Ti_(4)O and Ti_(5)O stoichiometries are predicted to be thermodynamically stable at certain pressure conditions.We found that these Tirich Ti–O compounds are primarily zero-dimensional electrides with excess electrons confined in the atom-sized lattice voids or between the cationic layers playing the role as anions.The underlying mechanism behind the stabilization of electrides has been rationalized in terms of the excess electrons provided by Ti atoms and their accommodation of excess electrons by multiple cavities and layered atomic packings.The present results provide a viable direction for searching for practical electrides in the technically important Ti–O system.
